There is an increasing demand for repair of or improvement to skin defects, which can be induced by aging, sun exposure, dermatological diseases, traumatic effects, heredity, and the like. Certain treatments may be used to improve skin defects by irradiating the skin with electromagnetic energy, which can lead to beneficial responses to improve the treated skin condition.
In particular, energy provided as optical radiation can be used in a variety of dermatological therapies. Optical radiation can include electromagnetic radiation that has one or more wavelengths in the visible spectrum range, ultraviolet radiation, and/or infrared radiation. Optical radiation can be absorbed by biological tissue, and the amount of such absorption may depend on the wavelength(s) and intensity of the radiation, the characteristics of the tissue and/or particular biological structures or chemical compounds therein, etc. Absorption of optical energy in biological tissue can generate heat and/or disrupt physical structures and/or certain biological functions in the tissue, which may in turn lead to beneficial or therapeutic effects over time.
Dermatological therapies which employ optical radiation can include, for example, removal of tattoos or hair, reducing an appearance of acne, or venous or pigmented lesions such as age spots, angiomas, spider veins, or port-wine stains, as well as wrinkle removal. In these exemplary applications, radiation can be typically delivered from an external energy source and provided to a target region of tissue. Often, it may be preferable to provide such energy as one or more pulses of energy having a large peak intensity and short duration to achieve a desired biological response in the tissue. Energy source which provide such energy can include, e.g., any one of a variety of lasers, electronic flashlamps, etc.
Optical energy may be directed from such energy sources to skin tissue using an optical arrangement such as, e.g., a waveguide or an optical fiber, and may further include one or more lenses, prisms, reflectors, etc. Such optical arrangements can subsequently focus or direct the energy onto the target region of interest. For example, such radiation can be preferentially absorbed by a portion of the skin or hair (e.g., melanin or blood vessels), resulting in localized heating.
A conventional apparatus used to provide energy (e.g., optical radiation) to skin or other tissue in such therapies may include a handpiece or the like, which can be easily repositioned relative to a patient. Such handpiece can be used to direct energy provided by the optical arrangement to one or more specific target regions to be treated.
Conventional methods and apparatus for applying energy to skin tissue as described herein may present many safety issues. For example, energy sources, such as lasers or electronic flashlamps can present a significant risk of overexposure, e.g., directing excessive amounts of energy to tissue and causing unwanted and potentially significant damage to tissue if such energy is not carefully controlled and applied. Safety precautions are often provided when using these exemplary energy sources. For example, an apparatus which includes a laser or other external energy source may often include one or more control arrangements that can regulate, limit, and/or shut off the energy output under certain conditions to reduce a risk of overexposure of skin tissue to the applied radiation. Such arrangements can include, e.g., a pulsing arrangement configured to pulse an energy source instead of providing a continuous energy, which can also prevent overheating of the energy source.
Alternatively, or additionally, a velocity or position sensor associated with a handpiece can be provided to prevent overexposure if such handpiece is translated over a region of the skin to direct energy onto the skin. A feedback arrangement can also be provided to control the energy source, and may be configured to reduce or interrupt an output of energy from the energy source if a dangerous condition is detected. Such feedback arrangement may be based on, e.g., a detected temperature, a reflectivity or other imaging property of the tissue being treated, etc. These safety devices add to the complexity and cost of the various energy application systems.
Conventional energy sources which can be used for such therapies may also require further safety precautions. For example, laser energy sources can require eye protection for operators of the apparatus and/or patients being treated, a limited access to the area where such energy source is being operated, extensive user training, etc. Such energy sources may also present a significant electrical hazard.
Conventional apparatus for providing optical energy to biological tissue may also be expensive, and access to such apparatus may be difficult for certain doctors or other practitioners for economical reasons. Therapies provided using such apparatus may also be costly for patients and/or health insurers. Also, certain apparatus may only be suitable for particular therapies. Thus, it may be impractical for a practitioner to have a variety of such apparatus for providing a range of therapies to patients based on, e.g., economic reasons, limited storage space in a medical facility, etc. Maintenance for such apparatus may also be costly.
Therefore, there may be a need to provide exemplary embodiments of apparatus and methods for application of optical radiation to skin tissue which combine safe, effective and economical treatment for improvement of dermatological defects and other therapies.